Swift Current
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Swift Current clear sky chart from 2005-11-06 to 2024-01-16.

This page is a summary of past forecasts. Even though it's based only on forecasts, some people use these pages as clue to a site's climate. But climate data based on actual observation should be preferred (if you can find it!).

Cloud, Transparency and Seeing forecasts are summarized individually. But because good observing conditions require a combination of minimum cloud cover, transparency and seeing, the individual forecast summaries can be difficult to interpret. The observing conditions section counts the combinations of conditions needed for common types of astronomical observation.

Observing Conditions

The following tables count the occurrence of the combinations of forecast and darkness conditions needed for different observations. Conditions are rated by by what percentage of the hours the observation would likely be attempted are usable.

Observation Type	Minimum conditions for hour to be usable				Out of hours
	Clear of Clouds	Transparency	Seeing	Sky Brightness
Planetary:	50%	(no limit)	Average	(no limit)	Nighttime Hours
Deep Sky:	70%	Average	(no limit)	5.9	Nighttime Hours
CCD Imaging:	70%	Below Average	Poor	(no limit)	Nighttime Hours

Percentages are of nighttime hours per month, or per year, when a particular observing conditions was met. Deep Sky percentages never exceed 50% because the moon is up half the time. Deep sky percentages are much lower for charts at high latitudes because of fewer dark hours in the summer.

Overall

By Month

Individual Forecasts

The length of each colored bar in the "occurrence of each Forecast" column is proportional to the number of times the chart forecast that color. The percentages are of the total number of hours per month, or per year, with a particular forecast. The colors as the same as those used in clear sky charts.

Note: Transparency probabilities are only counted for those hours that have 30% or less cloud cover. Seeing probabilities are only counted for those hours that have 80% or less cloud cover. If that's too tricky, try Observing Conditions instead.

Overall

		Occurrence of each Forecast	Data Points
Cloud Cover	Day	9% 8% 4 7% 6% 4 5% 5% 6% 8% 39%	74757
	Night	7% 8% 4 7% 6% 4 5% 5% 6% 8% 40%	75063
Transparency	Day	42% 7% 15% 23% 10% 1	74443
	Night	41% 7% 15% 23% 12% 2	74899
Seeing	Day	13% 10% 30% 29% 15% 4	14579
	Night	12% 9% 34% 32% 12% 1	24095

By Month

Percentage Cloud Cover SW (2006-)
Color Meanings: Overcast 90% covered 80% covered 70% covered 60% covered 50% covered 40% covered 30% covered 20% covered 10% covered Clear
Month	Days in Month		Occurrence of each Forecast	Data Points
January	1st to 10th	Day	7% 9% 5% 9% 8% 5% 7% 7% 6% 7% 31%	1329
	11th to 20th	Day	6% 10% 5% 10% 7% 5% 7% 5% 8% 10% 28%	1298
	21st to end	Day	4 11% 7% 10% 8% 5% 9% 10% 7% 7% 22%	1518
February	1st to 10th	Day	7% 11% 7% 12% 10% 4 7% 5% 5% 7% 24%	1614
	11th to 20th	Day	7% 11% 7% 9% 9% 5% 6% 6% 7% 7% 27%	1575
	21st to end	Day	4 10% 4 12% 9% 5% 7% 7% 7% 7% 28%	1340
March	1st to 10th	Day	6% 10% 6% 12% 10% 6% 6% 6% 6% 7% 26%	1839
	11th to 20th	Day	7% 11% 5% 9% 7% 3 5% 5% 7% 8% 33%	1980
	21st to end	Day	7% 11% 7% 10% 7% 4 5% 5% 6% 8% 28%	2245
April	1st to 10th	Day	8% 8% 4 7% 7% 4 7% 7% 7% 7% 35%	2160
	11th to 20th	Day	11% 12% 6% 8% 7% 4 5% 6% 6% 7% 28%	2229
	21st to end	Day	15% 10% 4 6% 5% 4 5% 4 6% 8% 35%	2425
May	1st to 10th	Day	13% 9% 4 6% 7% 3 6% 5% 6% 7% 34%	2520
	11th to 20th	Day	10% 6% 3 7% 6% 4 5% 5% 6% 8% 40%	2478
	21st to end	Day	19% 8% 3 6% 5% 4 5% 6% 5% 7% 32%	2830
June	1st to 10th	Day	15% 7% 3 5% 5% 3 5% 5% 7% 9% 34%	2700
	11th to 20th	Day	17% 7% 3 6% 6% 3 5% 5% 7% 7% 32%	2700
	21st to end	Day	9% 4 2 4 5% 4 5% 6% 7% 10% 44%	2700
July	1st to 10th	Day	5% 4 2 4 5% 4 5% 5% 7% 9% 50%	2700
	11th to 20th	Day	8% 4 2 5% 5% 2 4 4 6% 10% 49%	2700
	21st to end	Day	5% 3 1 3 4 3 5% 5% 4 8% 59%	2840
August	1st to 10th	Day	8% 4 2 5% 5% 3 4 4 7% 9% 51%	2507
	11th to 20th	Day	8% 5% 2 4 4 3 4 5% 6% 9% 51%	2327
	21st to end	Day	9% 3 2 4 3 3 4 4 4 8% 55%	2526
September	1st to 10th	Day	12% 5% 2 5% 4 3 5% 5% 5% 8% 46%	2160
	11th to 20th	Day	14% 7% 2 5% 4 3 4 5% 4 7% 46%	2160
	21st to end	Day	10% 6% 2 5% 5% 3 4 3 5% 7% 51%	1899
October	1st to 10th	Day	14% 10% 3 6% 4 2 4 4 4 7% 42%	1800
	11th to 20th	Day	8% 8% 3 7% 4 3 4 5% 7% 7% 43%	1800
	21st to end	Day	8% 11% 5% 7% 6% 3 6% 5% 6% 7% 37%	1769
November	1st to 10th	Day	9% 15% 5% 8% 8% 3 4 4 5% 5% 32%	1488
	11th to 20th	Day	6% 11% 4 11% 9% 3 4 6% 5% 7% 35%	1520
	21st to end	Day	8% 10% 5% 9% 7% 4 7% 5% 5% 8% 33%	1520
December	1st to 10th	Day	7% 7% 5% 11% 10% 6% 8% 6% 6% 6% 28%	1434
	11th to 20th	Day	3 8% 5% 11% 10% 5% 6% 7% 7% 6% 32%	1685
	21st to end	Day	4 8% 4 7% 6% 3 5% 5% 6% 6% 47%	2442
January	1st to 10th	Night	4 9% 4 8% 7% 5% 7% 7% 6% 10% 32%	2836
	11th to 20th	Night	4 9% 4 10% 9% 4 5% 6% 7% 7% 35%	2790
	21st to end	Night	4 12% 5% 11% 9% 6% 7% 8% 7% 7% 24%	2836
February	1st to 10th	Night	4 9% 7% 9% 8% 6% 7% 7% 8% 8% 27%	2362
	11th to 20th	Night	6% 13% 5% 10% 7% 5% 6% 6% 8% 8% 27%	2272
	21st to end	Night	5% 9% 5% 9% 8% 5% 7% 7% 7% 9% 31%	1916
March	1st to 10th	Night	5% 9% 6% 10% 10% 4 6% 7% 6% 8% 30%	2120
	11th to 20th	Night	7% 10% 4 8% 7% 3 5% 4 5% 8% 38%	1980
	21st to end	Night	7% 9% 5% 8% 8% 5% 5% 6% 6% 9% 31%	2111
April	1st to 10th	Night	7% 8% 3 7% 7% 4 6% 5% 7% 7% 39%	1800
	11th to 20th	Night	11% 13% 5% 9% 6% 3 6% 6% 4 6% 32%	1677
	21st to end	Night	11% 10% 4 7% 6% 4 6% 7% 4 7% 34%	1533
May	1st to 10th	Night	11% 7% 4 5% 4 3 5% 5% 8% 8% 40%	1440
	11th to 20th	Night	10% 6% 2 6% 4 2 5% 5% 7% 7% 47%	1417
	21st to end	Night	19% 7% 3 5% 5% 3 4 5% 6% 8% 35%	1443
June	1st to 10th	Night	12% 6% 3 5% 5% 2 4 5% 7% 9% 41%	1260
	11th to 20th	Night	13% 5% 2 5% 5% 4 5% 5% 7% 9% 39%	1260
	21st to end	Night	7% 5% 3 4 4 3 5% 6% 7% 9% 48%	1260
July	1st to 10th	Night	5% 3 2 4 4 2 5% 6% 6% 9% 54%	1260
	11th to 20th	Night	6% 3 2 3 3 2 4 4 6% 8% 57%	1260
	21st to end	Night	3 2 1 3 3 2 3 3 4 10% 65%	1477
August	1st to 10th	Night	7% 3 1 3 4 2 3 3 6% 9% 58%	1432
	11th to 20th	Night	6% 4 2 4 4 2 4 4 6% 9% 56%	1572
	21st to end	Night	9% 4 2 3 4 2 3 4 5% 7% 56%	1829
September	1st to 10th	Night	9% 5% 1 4 4 3 5% 4 5% 6% 54%	1800
	11th to 20th	Night	9% 7% 3 5% 5% 3 4 4 5% 9% 47%	1800
	21st to end	Night	9% 5% 2 4 3 3 4 5% 5% 9% 53%	2060
October	1st to 10th	Night	12% 8% 2 5% 4 2 4 4 5% 8% 45%	2160
	11th to 20th	Night	8% 7% 4 6% 4 3 4 4 6% 8% 46%	2160
	21st to end	Night	7% 12% 4 9% 6% 3 5% 5% 5% 8% 35%	2565
November	1st to 10th	Night	12% 13% 4 7% 6% 4 5% 4 5% 7% 32%	2590
	11th to 20th	Night	5% 10% 4 8% 9% 4 6% 6% 6% 7% 35%	2660
	21st to end	Night	6% 10% 5% 9% 7% 3 5% 6% 6% 9% 34%	2660
December	1st to 10th	Night	6% 9% 6% 11% 10% 5% 7% 5% 6% 7% 28%	2745
	11th to 20th	Night	5% 11% 6% 10% 8% 5% 6% 6% 6% 8% 30%	3506
	21st to end	Night	3 7% 3 6% 6% 2 4 4 5% 6% 53%	5214

Transparency (when cloud cover <= 30%)
Color Meanings: Too cloudy to forecast Poor Below Average Average Above average Transparent
Month	Days in Month		Occurrence of each Forecast	Data Points
January	1st to 10th	Day	50% 10% 13% 20% 8% 1	1329
	11th to 20th	Day	50% 8% 17% 18% 6% 1	1298
	21st to end	Day	55% 10% 14% 15% 5%	1518
February	1st to 10th	Day	58% 6% 11% 16% 9%	1614
	11th to 20th	Day	53% 8% 15% 15% 9% 1	1584
	21st to end	Day	51% 7% 14% 17% 9% 1	1340
March	1st to 10th	Day	56% 8% 15% 17% 4	1839
	11th to 20th	Day	48% 8% 17% 20% 8%	1980
	21st to end	Day	52% 10% 17% 16% 5%	2245
April	1st to 10th	Day	45% 8% 15% 21% 10% 1	2160
	11th to 20th	Day	53% 7% 13% 18% 7% 1	2232
	21st to end	Day	48% 6% 13% 25% 7% 1	2425
May	1st to 10th	Day	48% 7% 12% 24% 9% 1	2520
	11th to 20th	Day	41% 7% 13% 27% 11%	2482
	21st to end	Day	50% 8% 12% 21% 9% 1	2830
June	1st to 10th	Day	44% 8% 16% 22% 9% 1	2700
	11th to 20th	Day	49% 8% 13% 21% 8% 1	2700
	21st to end	Day	33% 10% 19% 28% 10%	2700
July	1st to 10th	Day	27% 9% 19% 30% 13% 2	2626
	11th to 20th	Day	30% 7% 17% 28% 16% 2	2619
	21st to end	Day	23% 6% 14% 34% 20% 3	2682
August	1st to 10th	Day	29% 8% 16% 31% 14% 2	2491
	11th to 20th	Day	29% 7% 20% 28% 13% 2	2327
	21st to end	Day	27% 5% 13% 31% 21% 2	2526
September	1st to 10th	Day	35% 6% 13% 25% 17% 4	2160
	11th to 20th	Day	37% 6% 15% 26% 14% 2	2160
	21st to end	Day	33% 6% 12% 32% 15% 1	1899
October	1st to 10th	Day	42% 5% 18% 25% 10%	1800
	11th to 20th	Day	37% 7% 14% 30% 10% 1	1800
	21st to end	Day	45% 7% 16% 25% 7%	1769
November	1st to 10th	Day	53% 7% 12% 19% 8% 1	1488
	11th to 20th	Day	48% 7% 15% 23% 7%	1520
	21st to end	Day	49% 7% 19% 20% 4	1520
December	1st to 10th	Day	55% 8% 15% 16% 5% 1	1434
	11th to 20th	Day	49% 8% 22% 15% 6%	1684
	21st to end	Day	36% 5% 14% 23% 11% 11%	2442
January	1st to 10th	Night	45% 9% 18% 19% 7% 1	2836
	11th to 20th	Night	46% 8% 18% 21% 6% 1	2790
	21st to end	Night	54% 9% 15% 15% 7% 1	2836
February	1st to 10th	Night	50% 8% 15% 17% 10% 1	2362
	11th to 20th	Night	52% 8% 15% 16% 9% 1	2273
	21st to end	Night	47% 7% 12% 22% 11% 1	1916
March	1st to 10th	Night	51% 7% 15% 17% 9%	2120
	11th to 20th	Night	45% 6% 16% 23% 9% 1	1980
	21st to end	Night	49% 8% 17% 17% 7% 1	2111
April	1st to 10th	Night	42% 6% 16% 24% 12% 1	1800
	11th to 20th	Night	52% 5% 12% 18% 10% 3	1677
	21st to end	Night	47% 9% 12% 22% 10% 1	1533
May	1st to 10th	Night	38% 7% 11% 27% 15% 1	1440
	11th to 20th	Night	34% 7% 14% 27% 16% 1	1418
	21st to end	Night	46% 7% 13% 23% 10% 1	1443
June	1st to 10th	Night	36% 8% 17% 26% 12% 1	1260
	11th to 20th	Night	40% 9% 13% 22% 15% 1	1260
	21st to end	Night	30% 10% 19% 29% 12% 1	1260
July	1st to 10th	Night	24% 8% 20% 31% 16% 1	1225
	11th to 20th	Night	25% 7% 14% 31% 20% 5%	1218
	21st to end	Night	16% 5% 13% 36% 27% 3	1395
August	1st to 10th	Night	24% 5% 17% 35% 17% 2	1424
	11th to 20th	Night	25% 6% 18% 31% 16% 3	1572
	21st to end	Night	27% 4 12% 27% 25% 4	1829
September	1st to 10th	Night	30% 6% 11% 27% 19% 7%	1800
	11th to 20th	Night	36% 6% 11% 26% 17% 4	1800
	21st to end	Night	29% 6% 13% 32% 17% 3	2060
October	1st to 10th	Night	39% 6% 14% 25% 15% 1	2160
	11th to 20th	Night	36% 5% 14% 29% 15% 1	2160
	21st to end	Night	46% 6% 14% 24% 8% 1	2565
November	1st to 10th	Night	51% 7% 13% 19% 9% 1	2590
	11th to 20th	Night	46% 7% 19% 20% 8%	2660
	21st to end	Night	46% 8% 20% 21% 6%	2660
December	1st to 10th	Night	54% 6% 14% 16% 7% 1	2745
	11th to 20th	Night	50% 9% 19% 16% 6% 1	3507
	21st to end	Night	31% 5% 11% 29% 16% 7%	5214

Seeing (when cloud cover <= 80%)
Color Meanings: Too cloudy to forecast Bad 1/5 Poor 2/5 Average 3/5 Good 4/5 Excellent 5/5
Month	Days in Month		Occurrence of each Forecast	Data Points
January	1st to 10th	Day	11% 15% 33% 26% 14% 1	180
	11th to 20th	Day	7% 14% 35% 27% 13% 4	171
	21st to end	Day	13% 14% 42% 23% 8%	236
February	1st to 10th	Day	11% 17% 44% 22% 6%	240
	11th to 20th	Day	10% 10% 46% 26% 6% 3	240
	21st to end	Day	7% 8% 44% 28% 9% 5%	198
March	1st to 10th	Day	12% 14% 41% 25% 7% 1	279
	11th to 20th	Day	11% 15% 38% 23% 10% 3	420
	21st to end	Day	13% 11% 34% 27% 12% 3	462
April	1st to 10th	Day	13% 17% 38% 25% 7%	420
	11th to 20th	Day	17% 14% 34% 27% 6% 1	412
	21st to end	Day	19% 11% 28% 31% 10%	505
May	1st to 10th	Day	14% 8% 24% 33% 17% 5%	603
	11th to 20th	Day	12% 8% 25% 31% 18% 5%	625
	21st to end	Day	20% 10% 19% 25% 21% 4	679
June	1st to 10th	Day	15% 10% 25% 31% 13% 5%	630
	11th to 20th	Day	21% 13% 29% 23% 11% 2	630
	21st to end	Day	11% 6% 26% 33% 19% 6%	630
July	1st to 10th	Day	8% 5% 23% 34% 25% 5%	621
	11th to 20th	Day	11% 7% 25% 33% 20% 4	618
	21st to end	Day	6% 7% 21% 35% 24% 7%	684
August	1st to 10th	Day	10% 5% 23% 35% 21% 6%	626
	11th to 20th	Day	12% 5% 25% 30% 22% 8%	465
	21st to end	Day	10% 6% 24% 37% 16% 7%	495
September	1st to 10th	Day	15% 9% 32% 27% 13% 4	450
	11th to 20th	Day	17% 7% 25% 35% 15% 2	450
	21st to end	Day	14% 10% 30% 28% 13% 4	356
October	1st to 10th	Day	23% 7% 23% 24% 20% 3	270
	11th to 20th	Day	9% 11% 36% 28% 13% 3	270
	21st to end	Day	14% 15% 39% 21% 9% 1	297
November	1st to 10th	Day	22% 9% 32% 29% 7% 1	270
	11th to 20th	Day	12% 22% 32% 24% 9% 1	270
	21st to end	Day	9% 14% 41% 20% 12% 3	270
December	1st to 10th	Day	8% 10% 48% 22% 7% 3	229
	11th to 20th	Day	9% 21% 44% 18% 6% 1	180
	21st to end	Day	10% 11% 36% 26% 15% 2	198
January	1st to 10th	Night	9% 14% 41% 25% 9% 1	950
	11th to 20th	Night	9% 15% 40% 28% 6% 1	930
	21st to end	Night	9% 17% 40% 25% 8% 1	990
February	1st to 10th	Night	8% 10% 35% 33% 12% 2	742
	11th to 20th	Night	11% 11% 39% 30% 9% 1	704
	21st to end	Night	8% 8% 31% 35% 16% 3	592
March	1st to 10th	Night	10% 11% 36% 31% 10% 2	720
	11th to 20th	Night	12% 10% 39% 28% 8% 2	720
	21st to end	Night	11% 10% 32% 33% 12% 2	725
April	1st to 10th	Night	11% 8% 35% 34% 11% 1	540
	11th to 20th	Night	16% 9% 36% 31% 8% 1	533
	21st to end	Night	16% 9% 29% 37% 8%	540
May	1st to 10th	Night	14% 6% 28% 33% 17% 2	540
	11th to 20th	Night	13% 6% 24% 38% 17% 2	531
	21st to end	Night	22% 7% 18% 33% 17% 3	475
June	1st to 10th	Night	16% 6% 29% 29% 16% 2	360
	11th to 20th	Night	17% 9% 26% 36% 13%	360
	21st to end	Night	11% 6% 23% 39% 19% 2	360
July	1st to 10th	Night	7% 4 24% 46% 19% 1	350
	11th to 20th	Night	10% 5% 28% 40% 16% 1	348
	21st to end	Night	4 4 28% 43% 19% 2	492
August	1st to 10th	Night	9% 3 26% 40% 19% 3	537
	11th to 20th	Night	7% 3 20% 43% 25% 2	534
	21st to end	Night	12% 3 26% 37% 21% 1	594
September	1st to 10th	Night	12% 4 31% 37% 14% 2	540
	11th to 20th	Night	12% 5% 25% 41% 16% 1	540
	21st to end	Night	12% 4 35% 37% 11% 1	706
October	1st to 10th	Night	18% 8% 29% 32% 13% 1	720
	11th to 20th	Night	13% 7% 35% 31% 11% 3	720
	21st to end	Night	16% 11% 38% 27% 7% 1	932
November	1st to 10th	Night	20% 10% 37% 27% 5% 1	925
	11th to 20th	Night	11% 16% 39% 25% 9% 1	950
	21st to end	Night	11% 13% 43% 25% 7% 1	950
December	1st to 10th	Night	11% 10% 39% 28% 10% 2	950
	11th to 20th	Night	10% 15% 40% 26% 8% 1	950
	21st to end	Night	12% 10% 38% 29% 9% 1	1045

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